Tem Investigation and Hardness Improvement of A N+ Implanted Al-Alloy

1995 ◽  
Vol 400 ◽  
Author(s):  
A.M. Serventi ◽  
M. Vittori Antisari ◽  
L. Guzman ◽  
A. Miotello
Keyword(s):  
Ion Beam ◽  
Al Alloy ◽  
Micro Hardness ◽  
Cross Sectional ◽  
Hardness Tests ◽  
First Results ◽  
Different Temperatures ◽  
Nitrogen Ion ◽  
A Current ◽  
Vickers Micro Hardness

AbstractThe surface modification induced by nitrogen ion implantation on the Al-alloy 7075 has been studied with the aim of understanding the microstructural evolution and the phase separation during the implantation process. 150 keV N2+ ions have been implanted at different temperatures from 373 K to 473 K, with a current density of 5–15 µA/cm2 on previously polished samples. The implanted dose was in the range 1 × 1017 N/cm2 - 5 × 1017 N/cm2. Vickers micro-hardness tests and friction coefficient measurements show a real improvement in the mechanical behaviour of the alloy after the treatment.TEM observations of specimens treated at low temperature with different ion dose have been carried out at 200 kV on cross-sectional samples, prepared by ion beam milling. First results show the presence of small AlN hexagonal precipitates whose evolution is followed as a function of the implanted dose.

Irradiation Effect of Nitrogen Ion Beam on Carbon Nitride Thin Films

2003 ◽  
Vol 792 ◽  
Author(s):  
Shinichiro Aizawa ◽  
Yuka Nasu ◽  
Masami Aono ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe
Keyword(s):  
Thin Films ◽  
Carbon Nitride ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Irradiation Effect ◽  
Carbon Filament ◽  
Cross Sectional ◽  
Nitrogen Ions ◽  
Nitrogen Ion

ABSTRACTIrradiation effect of low-energy nitrogen ion beam on amorphous carbon nitride (a-CNx) thin films has been investigated. The a-CNx films were prepared on silicon single crystal substrates by hot carbon-filament chemical vapor deposition (HFCVD). After deposition, the CNx films were irradiated by a nitrogen ion beam with energy from 0.1 to 2.0 keV. Irradiation effect on the film microstructure and composition was studied by SEM and XPS, focusing on the effect of nitrogen ion beam energy. Surface and cross sectional observations by SEM reveal that the as-deposited films show a densely distributed columnar structure and the films change to be a sparsely distributed cone-like structure after irradiation. It is also found that 2.0 keV ions skeltonize the films more clearly than 0.1 kev ions. Depth profiles of nitrogen in the films observed by XPS show that nitrogen absorption into films is more prominent after irradiation by 0.1 keV nitrogen ions than 2.0 keV ions.

Influence of Processing on Mechanical Properties of Hydroxyapatite

2008 ◽  
Vol 396-398 ◽  
pp. 587-590
Author(s):  
Marize Varella de Oliveira ◽  
Magna Monteiro Schaerer ◽  
Robson Pacheco Pereira ◽  
Ieda Maria V. Caminha ◽  
Silvia R. A. Santos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Processing Parameters ◽  
Molar Ratio ◽  
Micro Hardness ◽  
Sem Images ◽  
Cross Sectional ◽  
Load To Failure ◽  
Cylindrical Samples ◽  
Vickers Micro Hardness

In the present work, mechanical properties of a stoichiometric hydroxyapatite (HA), synthesized by hydrothermal method, with 1.66 Ca/P molar ratio are investigated as a function of the processing parameters. Cylindrical samples were processed by uniaxial compacting, followed by sintering, aiming to obtain high density HA samples. Density values were obtained by the geometric method and SEM images were taken from HA samples in order to characterize their topography and to determine the grain size for each set of samples. Vickers micro-hardness was measured for each set of samples. Compressive strength of cylindrical samples with 2.0 mean diameter/height ratio was measured reporting load to failure divided by the cross-sectional area of the samples. Vickers micro-hardness and compaction strength values of the samples were found to be in agreement with the relative density and grain size values.

Tuning the Exchange Bias in NiFe/Fe-Oxide Bilayers by Way of Different Fe-Oxide Based Mixtures Made with an Ion-Beam Deposition Technique

2007 ◽  
Vol 7 (1) ◽  
pp. 265-271 ◽  
Author(s):  
K.-W. Lin ◽  
P.-H. Ko ◽  
Z.-Y. Guo ◽  
H. Ouyang ◽  
J. van Lierop
Keyword(s):  
Exchange Bias ◽  
Exchange Coupling ◽  
Ion Beam ◽  
Hysteresis Loops ◽  
Bottom Layer ◽  
Cross Sectional ◽  
Fe Oxide ◽  
Different Temperatures ◽  
Spin Populations ◽  
Ar Gas

We have investigated the structural and magnetic properties of ion-beam deposited polycrystalline NiFe (25 nm)/Fe-oxide (35 nm) bilayers. A film prepared with an assist beam O2 to Ar gas ratio of 0% during deposition had a bottom layer that consisted of pure b.c.c. Fe (a = 2.87 Å) whereas films prepared with 19%O2/Ar and 35%O2/Ar had either Fe3O4(a = 8.47 Å) or α-Fe2O3 (a = 5.04 Å, c = 13.86 Å) bottom layers, respectively. Cross-sectional transmission electron microscopy revealed a smooth interface between the top nano-columnar NiFe and bottom nano-columnar Fe-oxide layer for all films. At room temperature, the observed coercivity (Hc ∼ 25 Oe) for a film prepared with 19%O2/Ar indicates the existence of a magnetically hard ferrimagnetic Fe3O4 phase that is enhancing the plain NiFe (Hc ∼ 2 Oe) by way of exchange coupling. A significant amount of exchange bias is observed below 50 K, and at 10 K the size of exchange bias hysteresis loops shift increases with increasing oxygen in the films. Furthermore, the strongest exchange coupling (Hex ∼ 135 Oe at 10 K) is with α-Fe2O3 (35%O2/Ar) as the bottom film layer. This indicates that the pure antiferromagnetic phases work better than ferrimagnetic phases when in contact with ferromagnetic NiFe. Hex(T) is well described by an effective AF domain wall energy that creates an exchange field with a (1 − T/Tcrit) temperature dependence. Hc(T) exhibits three distinct regimes of constant temperature that may indicate the existence of different AF spin populations that couple to the FM layer at different temperatures.

scholarly journals Investigation of Mechanical Properties of Friction-welded AISI 304 with AISI 430 Dissimilar Steels

2019 ◽  
Vol 1 (3) ◽  
pp. 8
Author(s):  
Anitha P ◽  
Manik ChandraMajumder ◽  
Saravanan V ◽  
Rajakumar S
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Micro Hardness ◽  
High Tensile Strength ◽  
Aisi 304 ◽  
Hardness Tests ◽  
Aisi 430 ◽  
Vickers Micro Hardness

In this paper, standard SS304 austenitic stainless steel and SS430 ferritic steel cylindrical rods were fabricated by friction welding process by varying the frictional pressure and forge pressure in order to understand the effect of process parameter. The tensile strength and Vickers micro hardness tests were conducted for each fabricated joint to evaluate the mechanical properties of the welded specimen. It was found that sample S5 with friction pressure of 90 MPa and forging Pressure of 120 MPa has the high tensile strength value of 637 MPa and 372HV at the interface region. A detailed microstructural analysis was performed at the interface to reveal interconnecting of dissimilar metals.

Phase Identification in Graphite Fibre-Aluminum Composites Using AEM

1990 ◽  
Vol 48 (2) ◽  
pp. 446-447
Author(s):  
G.J.C. Carpenter ◽  
S.H. Lo
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Bulk Material ◽  
Ion Beam ◽  
Analytical Electron Microscopy ◽  
Phase Identification ◽  
Al Alloy ◽  
Cross Sectional ◽  
Specific Strength ◽  
Al Composite ◽  
Graphite Fibre

The unique properties of graphite fibre - aluminum (Gr/Al) composites (high specific strength, high modulus and low coefficient of thermal expansion) have resulted in their use for components in space structures. However, the exposure to high temperatures required for the production of bulk material can result in interfacial reactions that cause a degradation in mechanical properties. Analytical electron microscopy (AEM) has been used to examine the phases formed during the heat treatment of such materials. The Gr/Al composite was examined in two forms: (a) as wire tows made up of AA6061 Al alloy, reinforced with Arco pitch-based P100 graphite fibres, coated with a thin layer of TiBx, and (b) as bulk composites produced by hot pressing a bundle of tows within a cladding of AA6061. Specimens for TEM were produced in longitudinal and cross-sectional orientations by preparing discs in a dimple-grinder, followed by ion-beam thinning. The specimens were examined in a Philips EM400T microscope, fitted with an Edax 9100 EDX system and a Gatan EELS.

Comparative techniques to investigate plastically deformed 5754 Al-alloy

2017 ◽  
Vol 31 (28) ◽  
pp. 1750255
Author(s):  
M. Abdel-Rahman ◽  
Mohammed Salah ◽  
Alaa M. Ibrahim ◽  
Emad A. Badawi
Keyword(s):  
Cold Work ◽  
Al Alloy ◽  
Micro Hardness ◽  
Degree Of Deformation ◽  
Positron Annihilation Lifetime ◽  
Peak Broadening ◽  
Mean Lifetime ◽  
Region 10 ◽  
Xrd Techniques ◽  
Vickers Micro Hardness

Cold work (compression) is an important method that produces dislocations mainly used to improve the mechanical properties of Al-alloys. The effect of deformation on 5754 Al-alloy was investigated by Positron Annihilation Lifetime Spectroscopy (PALS), Vickers micro-hardness (HV) and X-ray diffraction (XRD) techniques. The observation of results obtained by these techniques as a function of degree of deformation showed approximately the same behavior. Mean lifetime and Vickers micro-hardness values changed from 168.0 ± 7.0 ps and 32.0 ± 1.5 Hv, respectively, for the annealed (undeformed) sample to be 214.0 ± 7.0 ps and 43.0 ± 1.5 Hv, respectively, for saturated dislocation samples. Both PALS and HV results seems to be approximately constant above 8.0% degree of deformation which is the start of the saturated dislocation region. 10% degree of deformation is considered to be a threshold point or preferred orientation point obtained from XRD measurements after which saturation of dislocation is also obtained. Due to the variation in the interatomic spacing caused by plastic deformation, a significant increase in the peak broadening and line intensities of the XRD reflections is obtained.

A Study of Nanostructures of Thin Films in B–C–N System Produced by Pulsed Laser Deposition and Nitrogen Ion-Beam-Assisted Pulsed Laser Deposition

2004 ◽  
Vol 19 (3) ◽  
pp. 759-767 ◽  
Author(s):  
S. Bysakh ◽  
K. Chattopadhyay ◽  
H. Ling ◽  
J.D. Wu ◽  
C. Dong ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Ion Beam ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Nitrogen Ion ◽  
Micrometer Size

We report the synthesis of thin films of B–C–N and C–N deposited by N+ ion-beam-assisted pulsed laser deposition (IBPLD) technique on glass substrates at different temperatures. We compare these films with the thin films of boron carbide synthesized by pulsed laser deposition without the assistance of ion-beam. Electron diffraction experiments in the transmission electron microscope shows that the vapor quenched regions of all films deposited at room temperature are amorphous. In addition, shown for the first time is the evidence of laser melting and subsequent rapid solidification of B4C melt in the form of micrometer- and submicrometer-size round particulates on the respective films. It is possible to amorphize B4C melt droplets of submicrometer sizes. Solidification morphologies of micrometer-size droplets show dispersion of nanocrystallites of B4C in amorphous matrix within the droplets. We were unable to synthesize cubic carbon nitride using the current technique. However, the formation of nanocrystalline turbostratic carbo- and boron carbo-nitrides were possible by IBPLD on substrate at elevated temperature and not at room temperature. Turbostraticity relaxes the lattice spacings locally in the nanometric hexagonal graphite in C–N film deposited at 600 °C leading to large broadening of diffraction rings.

scholarly journals Novel Characterizations of Mechanical Properties for a Copper/Single-Walled Carbon Nanotube Nanocomposite Synthesized by Laser Surface Implanting

2020 ◽  
Vol 6 (1) ◽  
pp. 10
Author(s):  
Jay F. Tu ◽  
Nilesh Rajule ◽  
Sang Don Mun
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Compression Test ◽  
Ion Beam ◽  
Pure Copper ◽  
Laser Surface ◽  
Micro Hardness ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Hardness Tests

In our previous studies, we have developed a wet process, denoted laser surface implanting (LSI), to synthesize a copper/single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite as an implant onto the surface of a pure copper substrate. The nanostructure of this Cu–SWCNT composite was confirmed independently by several methods, including transmission electron microscope (TEM) images, which show discernable SWCNT clusters in nano sizes inside the copper matrix. The hardness was measured by micro-hardness tests to indicate over three times hardness over that of pure copper could be achieved. In this paper, we present several unique ways to further characterize the mechanical properties of the Cu-SWCNT nanocomposite. Nano-hardness tests are first performed to confirm that hardness improvement, about three times that of pure copper, is achieved, consistent with the micro-hardness test results. A new toughness measurement based on focus ion beam (FIB) bombardment was performed to demonstrate 2.5 times toughness improvement. Finally, a new compression test rig was designed to conduct plane strain compression test for an array of Cu-SWCNT implants. The results confirmed that the Cu-SWCNT nanocomposite exhibits a stress-strain behavior consistent with the results of the hardness and FIB tests.

Production, Sintering and Microstructural Characteristics of Ba2MgWO6 Ceramics

2005 ◽  
Vol 498-499 ◽  
pp. 523-528
Author(s):  
Leonardo A. Rangel de Aguiar ◽  
Camila M. Lapa ◽  
Ricardo Arthur Sanguinetti Ferreira ◽  
J. Albino Aguiar ◽  
Charles L. da Silva ◽  
...  
Keyword(s):  
Communication Technology ◽  
High Frequency ◽  
Communication Systems ◽  
Structural Characteristics ◽  
Dielectric Resonators ◽  
Micro Hardness ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Hardness Tests ◽  
Vickers Micro Hardness

In the present era, high technology wireless communication and mobile communication systems require advanced ceramics as high frequency dielectric resonators. In the present work we have produced Ba2MgWO6 (BMW) ceramics and studied its structural, microstructural and mechanical properties. Ba2MgWO6 (BMW) ceramics belong to the Ba2MgTaO6 (BMT) and Ba2ZnTaO6 (BZT) ceramics family, which is well known ceramic material for the communication technology. There is little information available on materials characteristics of BMW ceramics. Structural characteristics of BMW ceramics were studied by X-ray diffractometry. Microstructural characteristics were studied by scanning electron microscopy and mechanical behavior was tested by Vickers micro-hardness tests on sintered BMW bodies. This article reports these characteristics of BMW ceramics and discusses its implications on application viability.

Morphology and Thermal Stability of Metastable Precipitates Formed in an Al-Mg Alloy Aged at 373K and 473K

2015 ◽  
Vol 799-800 ◽  
pp. 212-216
Author(s):  
Koichiro Fukui ◽  
Ryota Watanabe ◽  
Mahoto Takeda
Keyword(s):  
Isothermal Aging ◽  
Precipitation Hardening ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Precipitation Behavior ◽  
Dsc Measurements ◽  
Β Phase ◽  
Hardness Tests ◽  
Thermal Stability Of ◽  
Vickers Micro Hardness

The present work has investigated precipitation behavior in an Al-17at%Mg alloy isothermally aged at 373K and 473K, by means of Vickers micro-hardness tests, DSC measurements and TEM observations. The present DSC measurements have revealed that the metastable β′-phase precipitates mainly contributed to precipitation hardening of this alloy in isothermal aging at 373K and 473K. The TEM observations have confirmed that the β ' phase precipitates were formed in the {001} planes of Al matrices in platelet shapes.

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